Agricultural combines are large machines that harvest, thresh, separate and clean harvested crop, planted agriculturally that carries corn. The clean corn thus received is stored in a corn tank arranged on the combine. The threshed out straw is usually either chopped and distributed over the field across the width of the cutter head or conducted around the straw chopper and deposited in a swath across the field without being chopped, in order to be able to take it up subsequently with a baler. The harvested crop remains, such as chaff and small straw particles, remaining at the rear outlet of the cleaning arrangement are distributed across the field by a chaff spreader or they are conducted through the straw chopper and distributed across the field.
DE 199 08 111 C1 describes a combine with a straw chopper and two impeller blowers arranged side by side alongside each other downstream of the straw chopper for the wide spread distribution of the straw across the field. The outlet of the straw chopper and the inlet of the impeller blowers arranged in a housing, that include the impeller blades that are flat in themselves and rotate about a vertical axis, are arranged in a single plane for the sake of transfer of harvested crop without change of direction.
US 2007/0015556 A1 describes a combine with a straw chopper in which the outlet of the straw chopper supplies the following impeller blowers from below at their circumference at an acute angle. The impeller blades of the impeller blowers are flat in themselves and are slanted upward in the direction of the axis of rotation.
WO 2008/156419 A1 describes a similar arrangement of the straw chopper; however the flow of harvested crop is deflected by a sheet metal plate downstream of the straw chopper, so that it is directed at the impeller blower in the radial direction but at a relatively sharp angle. The impeller blades of the impeller blower are flat in themselves.
U.S. Pat. No. 7,390,253 B2 describes a combine with impeller blowers rotating about horizontal axes extending in the direction of operation, each of which includes three impeller blades to the rear of which bevels are applied.
U.S. Pat. No. 6,343,896 B1 that is seen as forming a class, proposes a combine with impeller blowers rotating about horizontal axes extending in the direction of operation, each of which includes impeller blades curved to the front, in the direction of rotation, whose axial extent increases in the outward direction.
In the aforementioned impeller blowers with impeller blades that are flat in themselves, the harvested crop remains are delivered and distributed across the entire axial length of the impeller blades. Thereby they provide a corresponding surface of attack to a side wind that may result in an undesired sideways drift of the harvested crop remains. The impeller blades according to U.S. Pat. No. 6,343,896 B1 are not able to efficiently convey away harvested crop entering in the central region due to their geometry.